I have a guppy with a problem!!!

I doubt the salt would really hurt unless it 'feeds' whatever your guppy has. I add a little salt anytime I do a WC, introduce new fish, etc and it's never hurt anything. But I am no expert. I do hope you figure it out because that is a very pretty guppy you got there.
 
A breeding pair of angels, 1 male guppy, 2 female guppies....no one else shows anything at all. He is acting normal, just has these spots. I guess I will stick with the salt and warm temp for now.
 
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